Differential motion for wire-stitchers or like machines.



A. H. MAYNARD.

DIFFERENTIAL MOHQN FOR WLRE-STITCHERS 0R LIKE MACHINES. APPLICATION mum [VIM/26,1916.

Patented Feb. 5,191

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APPLICATION. FILED MAY 26 I916. mamm 2 J a J 2. 5%

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ABTHUB H. MAYNARD, 01E WARWICK, RHODE ISLAND, ASSIGNOB T BOSTON WIRE B'IITCHJEB COMPANY, OF AUGUSTA, MAINE, A CORPORATION OF MAINE.

DIFFERENTIAL MOTION FOR WIRE-STITCHERS 0R LIKE MACHINES.

Specification of Letters-Patent;

Patented Feb. 5, IFIA Application filed May 26, 1916. Serial No. 100,022.

chines, of which the following is a specifi- My invention relates to wire-stitching or stapling machines for forming staplesand inserting them through overlapping thicknesses of paper, cardboard or other material to fasten their parts together. The invention consists particularly of an improved diflerential motion for operating the benderbar, which forms the staple from lengths of 'wire fed thereto, and the coordinated mechanism for driving the staples through the work and clenching their legs thereagainst. The objects of the improvement are to simplify the operating-mechanism of the machine; to increase its durability; and

' to render the cooperation of the bender-bar and staple-driver more eiiicient for the purpose intended and also adaptable to a wlder range of Work.

The manner and means for carrying out these improvements are fully described'in the following specification, illustrated by the accompanying d.rawin,g ;s,'in which like reference characters designate like parts. In the drawings:

Figure 1 is a side view in vertical section of a stitcher-head illustrating the essential elements of the staple-forming and driving mechanisms and showing their connection with the operating-means therefor;

Fig. 2', a front elevation of the operatingmeans for the reciprocating bender-bar and staple-driver, showing these latter elements approaching the end of their upward stroke;

Fig. 3, a similar view showing the bender-bar'at the start of its downward stroke and the driver in position just previous to the beginning of its stroke downward;

Fig. a, a similar view illustrating the bender-bar at the end of its downward stroke with the driver approaching this end of its movement; and I Fig. '5, a similar view showing both the bender-bar and driver in lowermostposition in the act of completing the clenching of the staple in place.

Referring first to Fig. 1, my improved mechanism is here shown as applied to a vertical type of stitcher-head such, for.instance, as that described in U. S. Patent No. 970,461, granted Sept. 20, 1910, to T. A. Briggs. It is to be understood, however, that my improvements are adapted for use with other forms of stitcher-mechanism and might also be employed in connection with other machines of asimilar nature. In Fig. 1 the stitcher-head is shown in section to illustrate theoperating-mechanism inclosed is attachedto the front of, a horizontal arm A. The arm A extends forwardly from the main standard or frame of the machine, not here illustrated, and overhangs 'a horizontal table or work-support T on which the ma terial .to be stitched is placed to bringF it into position beneath the bonnet B.

work-support T carries a clencher-block t.

at its outer end which cooperates with the stitcher-mechanism in the bonnet B to clench the legs of the staple in place, see

'Fig. 5, or in some instances movable clenchbut these elements form no part of the present invention and theygare netherein shown or described. 7

Fastened to the front of the head or bonnet B are two opposite, sidemembers or vertical guide rails G, only one being shown in Fig. 1, on which the reciprocating parts of the mechanism slide. .These latter consist essentiallyof a driving-bar D; a driver .bar D connected to be reci rocated-therein the bonnet B which forms a part of, or i I with; a staple-driverlD'j earned at the lower 1 end of the driver-bar D; and the stapleformer or bender-bar C arranged to be re-, ciprocated independently of the other slidconnected at the rear by a web see Fig.

1. The opposite sides 0 c of the benderbar C project downwardly beyond, the lower end of their connecting-web 0 to. form' the parallel legs 0 c which cooperate with a forming-anvil F, illustrated only in Fig. 1, to bend the legs of the staple at ri ht=angles to its top. Mounted to slide in 't e central slot 0 of the bender-bar C is the driverbar D, which is of substantially plate-like construction with its sides fitting between the sides 0 0 while its upper end projects above the top of the bender-bar. At itsupper end the driver-bar D has a tongue-andgroove connection at d with the lower end of the driving-bar D to adapt the two members to operate together as one part. The staple-driver D consists simply of a relatively thin plate let into the front face of the driver-bar D and fastened in place in any suitablemanner to provide for its removal for repair or replacement." The sides of the driver D are formed with splines d d fitted to slide in grooves 0 c in the sides 0 c of the bender-bar C to retain the driver-bar in place in the slot 0". The lower edge of the driver D is adapted to make contact with the top of the staple m, see Fig. 5, to drive its legs through the work X and clench them in place against the under side thereof, as more fully explained hereinafter. p

The forming-anvil F is rotatably supported in a sleeve-like bearing f mountedon one side of the bonnet B, and is adapted to slide longitudinally of its axis. Its inner,"beveled end isrecessed with a slot f adapted to receive the wire fed down from the top of the machine and severed into lengths for the staples, the means for these last-named operations not being herein described or illustrated as they may be of any usual construction as well known in the art.

bend themdown at right-angles to the central portion of the wire held in the slot f to form the.opposite, parallel legs of the staple. After the staple has thus been formed the driver D descends against its top and as the lower edge of the driver comes into engagement with the forward, beveled end of the anvil F it slides the latter back out of the way. The arrangement and method of cooperation of these last-named parts are explained in-detail in the patent to Briggs before referred to and will not, therefore, be herein further described. Pivotally mounted on the rear of the benderbar Cis a staple-supporter H arranged to adapt its lower end to swing into position between the legs 0, 0 to hold the staple in place while it is being 'driven through the work. This device is similar in function to other arrangements commonly in use, and as it has no relation to the present invention it will not be herein described in detail.

As before explained the driving-bar D with its connected parts and the bender-bar C are arranged to slide up and down on the guide rails G, and the means for reciprocating them with a differential motion, to effect their synchronous operation in forming and driving'the staple, ,constitute the essential features of my improvement. Referring particularly to Fig. 1, the drive-shaft S carries a crank-disk J keyed to its outer end at .j, to rotate therewith, and serving as the prime-mover for all of the several reciprocating parts hereinbefore referred to. On the outer face of the disk J is an eccentric hub K secured thereto by two pins 7c, is, see Fig. 2, riveted through the disk as shown in Fig. 1. One of the pins k is formed with a collar'or flange k abutting the front face of the hub K and an enlarged head or extension k? projecting outwardly therefrom. The head lc u serves as a crank-pin for a connecting-rod L pivotally journaled therebar D, as shown most clearly in Fig. 1, and

in this, manner the bar D and the parts carried thereby are connected to the crank-disk J to be reciprocated therefrom with a stroke equal to the throw of the crank-pin 71:. As illustratedin Fig. 1, the connecting-rod L is providedwith an oil-hole Z at its upper end which leads to an oil-groove Z, scored on the periphery of the crank-pin k, and thence communicates with a duct Z for conducting the lubricant down to the wristpm m.

The bender-bar O is also connected by a pitman N to be reciprocated from the crankdisk J, but with a different timing of its movement and with a variable length of stroke as next described. .The pitman N is constructed for,longitudina'l expansion and contraction and comprises two telescoping members N and O. The upper member N 'is formed with a strap-like bearing n surmemo).

downwardly from the eccentric-strap n is an arm n bored longitudinally at n to receive the rod 0 which forms the sliding extension of the pitman N. The rod O is inserted through the oil-hole n in the member N and is formed with av head 0 which seats against the bottom of the hole to limit its sliding movement in the bore n. The lower endof the rod 0 is screwed into a T-shaped bearing-member O and held in place by a set-screw 0. The bearing-member O is formed with a cross-bore 0 in which is ournaled a wrist-pin P riveted or otherwise secured to the rear of the bender-bar C. The upper arm of the member 0 isreduced in diameter at o to receive the end of a-coiled spring R which bears against an annular shoulder 0 The upper portion of the spring R surrounds the arm n of the member N with its end bearing against a shoulder a".

The tendency of the spring R will be to maintain the parts of the pitman N extended to the full length as illustrated in Fig. 1, with the head 0 of the rod 0 seated against the bottom ofthe bore 11/. .The spring R mav be compressed, however, to allow the rod 0 to slide within the member- N to reduce the length of the pitman, and thereby the distance between the axes of the crankpin 70 and wrist-pin m. In this manner the length of stroke of thebender-bar (J is made .variable in accordance with the thickness of machine. The method of operation of the cemplete mechanism is as follows:-

' ward and upward strokes. Referring to Fig.

3, it will be observed that the' pitman N,

connected to the eccentric hub K,;will commence its downward stroke immediately-the center of the hub K passes across the verti-"-- cal plane of the axis of the crank disk ill;

while the connecting-rod D will not start to descend for an interval thereafter, or until the center of'its crank-pin has 'passed'the same point. In this way the bender-bar C is caused to first move downwardly to bring its lower end into cooperation with the form-' ing-anvil to bend down the legs of the staple, as before explained, and meanwhile the driver-bar D follows the bender-bar in its downward stroke, but with a differential movement therebetween. Fig. 4 illustrates the parts in their relative positions at the instant that the lower ends of the bender-bar legs 0 c" come'into contact with the work X being stapled, which, as before explained, is supported on the work-table T. As the work X, its further movement will be rebender-bar C is brought down against the sisted thereby butthe driver-bar D will still 1 continue to move downward, causing the driving-bar D and its attached staple-driver D- to slide in the slot 0 of the bender-bar. Meanwhile, the formed staple a: is held by the staple-supporter H shown in-,Fig. 1, with its legs engaging the shallow grooves 0 c in the legs a, 0* of the bender-bar G as illustrated in Fig. 4. Now, as the driver D continues to slide downward -in the bender-bar C, its lower edge bearing against the topof the staple-w will force the latter down and drive its legsthrough the stock X. As the legs of the staple protrude through the under side of the work X they come into, contact with the clencher block 23, see Fig. 5, and

are thereby'bjent over and clenchedagainst the material in the usual manner.

Referring to Figs. 4 and 5, it is to be noted that during this last-described movement .of the driver. D to drive and clench the staple wjin place, the bender-bar .C remains at'rest. This pause or dwell of the.

bender-bar at the bottom of its stroke is provided for by the compression of its springv extended pitman N in the following manner: As shown in Fig. 4 the bender-bar C reaches the lower limit of its movement, as defined by thethickness of the work- X, be-

fore the eccentric hub K reachesthe lowermost end of its stroke. In other words, the bottom of the bender-bar C comes. into contact with the work X before the axis of the hub K, indicated at 3 in Fig. 4, has reached the vertical. plane of'the axis of the crankdisk J represented by the dot and -dash" lines 4-4. Hence, as the axis of the hub K passes from the point 3, illustrated in Fig. 4:, to point 5 as shown in Fig. 5, the pitman N will be required to yield, it s parts 0' and N telescoping and contracting the spring R.

After the clenching of the staple has been a completed the driver D starts to ascend as its crank-pin passes. across the vertical plane l tiof itsaaxis of rotation. At this instant the center of the eccentric hub K will have I reached the position 5 as shown in Fig. 5 and the bender-bar C will start to rise with the driver D. It will be noted item the dots and-dash lines 6 6and 77 in Fig. 2, that the radial distance of the center of the crank-pink from the axis of the disk J is greater than that of the center of the hub K and'hence the parts operated from the connecting-rod L will have a longer stroke "bender-bar 'Ihis results in the driver D being raised and a faster movement than that of the operated from the pitman N.

more quickly than the bender-bar C to cause it to slide upwardly therein so that it will be out of the way when the bender-bar starts its descent again to form the next staple. In other words, the'bender-bar L. and driver D are operated with a difi'erential motion which causes the bender-bar to descend first to form the staple and the driver to follow it be insert the staple in place, after which the driver is quickly retracted with respect to the bender-bar to allow the parts to act again as first described, the reciprocal move-, ments of the parts being synchronously continned in successive cycles. In this manner .the bender-bar C is maintained in contact with the work X during the interval while the staple is being driven therethrough' and clenched in place. Through'this provision the werk is held in position against accidental displacement 'so that the staple will be applied in proper relation to the seam being stitched.

Another object of this improved method of action of the bender-bar is to ada t the stitching-mechanism tooperate on di erent thicknesses of stock without requiring ad-v justment in the-length of its stroke. For instance, if the thickness of the stock should vary slightly, or if more than. the prescribed "thicknesses required to be stitched should be placed in the machine, inadvertently or through accident, the bender-bar will automatically accommodate itselfto such variations, wlthin certain limits, through the aryrugged,'capable of resistingsevere stresses and proof againstdeterioration or damage n use. Furthermore, my lmproved device is adapted to a wider range of work without adjustment than similar mechanisms previ-v ously employedfor the same purpose, and is self-conforming to allow for irregularities in the thickness of the stock.

Various modifications might be made in the construction and. arrangement of the parts of the mechanism and the manner of applying it to difierent types of apparatus without departing from the spirit or scope of the invention; therefore, without limiting myself to the exact embodiment shown, what I claim is -1. In a difl'erential-motion for wire-stitching machines or other apparatus, the combination with a rotating crank-disk, of an eccentric hub on said disk, a longitudinally contractible pitman journaled on said hub to be reciprocated therefrom, a crank-pin arranged eccentric to the center of the hub, and a connecting-rod jour aled on the crank-pin to'be reciprocated with a diiferential movement withrespect to the pitman.

2. In a mechanism ofthe class described, the combination with a rotating crankshaft, of-an eccentric hub revolving about the axis of the shaft, a crank-pin revolving therewith with a eater length of throw, a connecting-rod 1ournaled on the crank-pin to be reciprocated therefrom, and a longitudinally contractible pitman journaled on the eccentric hub to be reciprocated therefrom and adapted to be contracted to equalize the operative eifect of its stroke with the stroke of the connectin -rod.

3. In a mechanism 0 the class described, the. combination with a rotating crank-shaft, of a connecting-rodadapted to be reciprocated therefrom, a pitman also connected with the crank-shaft to be reciprocatcd with a differential motion with respect to the com necting-rod, said pitman being longitudinally contractible to equalize the operative 'efi'ect of its stroke with that of the connecting-rod.

4. In a mechanism of the class described, the combination with a rotating crank-shgft. of a connecting-rod reciprocated fromsaid crank-shaft, and. a resiliently-extended pitman .connected to be .reciprocated from the crank-shaft with a differential motion with respect to the connecting-rod but adapted to contract longitudinally under pressure to equalize the operative effect of its stroke with that of the connecting-rod.

5. In a mechanism of the class described, the. combination with a rotating crank-shaft, of a connecting-rod reciprocated from said crank-shaft, a longitudinally contractible pitman also connectedto be. i'eciprocated from the crank-shaft, a member connected with the pitman to be reciprocated thereby,'and a second member arranged to slide in the first member and adapted to be reciprocatediwith a differential motion in relation thereto through its connection with the connecting-rod.

tractib aaeaaci 6. In a mechanism of the class described,

the combination with a rotating crank, of a connecting-rod reciprocated therefrom, a revolving eccentric hub, a longitudinally cone pitman connected to be reciprocatedthereby, a sliding member connected to be reciprocated by the pitman, and a second member slidable in the first member and connected "to be reciprocated from the connecting-rod with a longer stroke and faster motion than that of the first member.

7. In a wire-stitching or stapling-"'machine, the combination with a rotating.

crank-shaft, of a resiliently-extended longitudinally-contractible pitman connected to be reciprocated therefrom, a bender-bar connected tobe operated 'from the pitman to form the staples from lengths of wire fed thereto, a connecting-rod also reciprocated with afaster rate of movement than that of the bender-bar.

9 In a wire-stitching or stapling machine,

the combination with a reciprocable benderbar for forming staples from lengths of wire feel thereto, of a driver cooperating there with for driving the formed staples through the work, a rotatingcrank-disk, an eccentric hub on said disk, a pitman journaled on said hub and connected to reciprocate the bender-bar therefrom, a crank-pin on the crank disk arranged eccentric to the center of thehub, and a connecting-rod journaled on the crank-pin and connected to the driver to reciprocate the latter with a difierential motion in relation to the bender-bar.

10. In a wire-stitching orstapling machine, the combination with a reciprocable bender-bar for forming staples from wire fed thereto, of a reciprocable driver for I chine, the combination with a reciprocable v bender-bar for forming staples from wire from the crank-shaft with a longer stroke driving the staples through the work, a lonfed thereto, of a reciprocable driver cooperating therewith for driving the staples through the work, means to reciprocate the driver, means to reciprocate the bender-bar,

and a resilient telescoping connection be-' tween the bender-bar and its reciprocatingmeans, whereby said bender-bar is held against the work with a yieldable pressure during in place.

12. In a Wire-stitching or stapling ma-' chine, the combination with a reciprocable bender-bar for forming the staples and guiding them into position against the work, of a reciprocating driver cooperatin with the bender-bar for driving the stap es through the work, and a resiliently-extended longitudinally-contractible connection for reciprocating the bender-bar to force it against the work with a yieldable pressure while the staple is being driven therethrough.

13. In a wire-stitching or stapling machine, the combination with a reciprocable the operation of setting the staple V bender-bar for forming the staples and guidingthe bender-bar to adaptit to act against the work being st'apledlwith a yielding pres sure.

chine, the combination with a relatively stationary anvil for holding lengths "of wire fed thereto to be formed into staples, of a reciprocable bender-bar for cooperatingwith the anvil to bend down the legs of the staple, means to reciprocate the bender-bar, and a longitudinally contractible connection between the reciprocating-means andthe bender-bar to adapt the latter to act with a variable stroke and a yielding pressure against the work being operated upon.

15." In a wirestitching or stapling ma- 1 16. In a wire-stitching or stapling ma- I chine, the combination with a reciprocable bender-bar for formingstaples from lengths of wire fed thereto, of a contractible pitman for reciprocating said bender-bar, said pit man comprising an eccentric-strap having a depending arm formed with a longitudi nal bore, a rod slidable within said bore and carrying. a bearing for a wrist-pin at its end, and a. coiled spring surrounding the arm and rod and acting against the endrat 7 hearing of the latter tnormally maintain the nn-ta in extended relation '1? A longitudinally--: ontraetibie pitman fem? wire-stitchers'or F machimsr cornpris ing member former with an eeee-nt' strap and. arm extemiing therefrom, mm arm having a longitudj bore eommunicav ing with larger bore extending axially therefrom a. rod slidani in the smaller bore bottom of the .11 rger bore, a T-headed bearing secured ta the outer end of the TOd, and a coiled spring surrounding the arm and the rod. and acting against the T-headed memher no maintain the parts in extended relation In testimony whereof I aflix my signature.

AR'EHUR MAYNARD.

and: formed with a head seated against the 10 

